It is known that above the door of an aircraft, notably a transport airplane, there is generally a cover plate which is arranged on the external face in order to close off a space between the door and the door surround mounted on the fuselage of the aircraft, this space being allocated to the movement of the door as the latter is opened or closed. This cover plate notably has the function of preventing the door from becoming jammed with ice or snow, and of improving aerodynamics.
Because the stiffness of this cover plate, and therefore the pressure with which this cover plate presses against the fuselage, has a direct effect on the force required to open and close the door, cover plates that are flexible are generally provided in order to make movements of the door easier.
However, a flexible cover plate carries, at a leading edge, a risk of vibration caused by the air flow. This phenomenon may cause the space between the door and its surround to open up and/or may generate noise during a flight.